Hull construction



NOV. 15, 1949 GARMONT 2,488,183

HULL CONSTRUCTION Filed Aug. 22, 1944 W) i7 EH'IHHVIVENTOR. HARRY/,4. (memo/v7,

5 Shets-Sheet 1 1 Nov. 15, 1949 H, GARMONT' 2,488,183

HULL CONSTRUCTION Filed Aug. 22, 1.944 3 Sheets-Sheet 2 INVENTOR. HARRY H. GAR/v04:

ATTOR/Vfy Nov. 15, 1949 H. H. GARMONT 2,438,183

HULL CONSTRUCTION Filed Aug. 22, 1944 5 Sheets-Sheet s INVENTOR. HARR Y H. 5/42/1404;

Patented Nov. 15, 1949 a r r UNITED" STATES PATENT OFFICE HULL CONSTRUCTION Harry H. Garmont, Jacksonville, Fla. Application August 22, 1944, Serial N0. 550,535

This invention relates to new and useful improvements in boat hulls especially designed for water craft intended to travel at a speed in excess of 20 knots.

Conventional boats in this category are subject to a bow air resistance, under hull suction "resistance and stern vacuum, and all three of these factors must be considered as the rate of speed of the boat varies.

Boats in this class are noticeably unstable, both when idle and in motion, this being due principally to the lack of any inherent ballasting factors plus existing hull designs now in use. An important object of the invention is to provide a hull construction designed to increase the speed and reduce the water resistance of power boats, while simultaneously promoting increased stability.

Another object of the invention is to provide a hull construction designed to relieve the various natural resistances a boat normally encounters, by directing air as a relief medium to the affected parts of the craft.

Still another object of the invention is to provide a hull construction wherein air is taken in at the bow, thus relieving bow resistance, and wherein this captured air is utilized to further relieve water resistance at the bottom of the craft and vacuum at the stern.

A further object is to provide in a craft of the character stated a water trap in which water will assume a natural level consistent with that at the outside of. the boat, to ofier a ballast or balancing efiect while the craft is idle.

Other objects and advantages of the invention shall become apparent to the reader of the following description.

In the drawings:

Figure 1 is a top plan view of the entire boat.

Fig. 2 is a side elevation with the stern portion broken away.

Fig. 3 is a longitudinal horizontal section taken on line 3-3 of Fig. 2.

Fig. 4 is a front elevation showing the bow.

Fi 5 is a, rear elevation showing the stern.

Fig. 6 is a longitudinal vertical section taken on line 66 of Fig. 3.

Fi 7 is a transverse section taken on line '!-'I 01 Fig. 6.

4 Claims. (Cl. :1146.6.5)

Fig. 8 is a cross section taken on line 88 of Fig. 6.

Fig. 9 is a cross section taken on line 9-9 of Fig. 6.

Referring to the drawings, wherein like numerals designate like parts, numeral 5 generally refers to the hull.

An engine compartment 5, and an occupant compartment 1 are provided within the hull, and these are surrounded by a bulkhead or watertight wall 8, the side portions of which are spaced from the sides of the hull 5 to define air tunnels 9, 9.

In the occupant compartment 5 are front and rear seats and preferably under the rear seat is a water trap generally referred to by numeral l0, the same forming an important part of the present invention.

The bow of the boat is undercut on a plane oblique to the water line and this area of the bow is not only concave but formed with a transverse opening II for the admission of air. This undercut portion has a short transversely elongated lip I2 protruding into the opening and the bottom of the boat from this lip inwardly, as denoted by reference character 12 is formed with a fiat area l2 gradually reducing in width toward amidship. Aside from this fiat middle "portion, the bottom of the boat is concave and the curvature of this gradually decreases toward 'the stern. As is apparent in Fig. 4, the bow end 'of the bottom reaches a shape of substantially inverted V-shape. As noted in Fig. 4, the side portions of the hull, at the bow, are slotted or constructed to form 'open grills l2, so that air is taken in at these points, as well as through the opening or mouth I I.

Just inside of the mouth I! is a horizontal V-shaped divider ll for the purpose of deflecting air to both air tunnels 9. The forward end of the divider is just over the lip 12.

The stem of the boat has an outlet opening l3 over which grill bars 13 are disposed (see Fig. 9).

Now referring to the water trap l6, this trap consists of a pair of bulkhead walls [4 and IS with a short wall I 6 between the same. These walls l4, l5 and I6 extend from one side of the bulkhead enclosure 8 to the other, the wall I5 serving as an aft auxiliary protection for the water trap. J j r Due to the structural requirements along the center of the boat, the water trap is divided by a partition 11. At opposite sides of the partition H, the bottom of the boat is formed with elongated openings 18. Above the normal water line, the side walls of the bulkhead enclosure 8 are formed with elongated openings l9, communicating the air tunnels 9, 9 with the water trap H].

The bottom of the boat at the aft edge of each of the openings I8 is beveled as shown in Fig. 6, and this has a tendency to allow for a more effective action of the bottom suction on air available through the trap ID, with the result that an abundant supply of air is drawn to the bottom side of the boat and directed to-the aft underskin, thus alleviating water resistance. This promotes a higher riding position of the stern and in effect provides an air film between.

the water and the bottom skin of the craft.

As shown in Figs. 6 and '7, the rear seat which is denoted by numeral 20 is intended to rest snugly on the walls M to make the compartment thereunder substantially air-tight.

In the operation of the structure above described, it can be seen that when the boat is idle, water will assume a normal level in the water trap between the walls l4, l6 and the presence of this column of water will serve as a ballast or balancing factor contemplated to prevent rolling or tossing of the vessel, which is at present quite an annoyance to owners of small boats built for speed.

It will now be seen that the water trap has a two-fold function, for in addition to stabilizing the boat while idle, this trap will empty of water when the boat is set in'motion due to the-natural suction that will be found under this portion of the boat.

The suction which Will empty the water trap of water will also act on the air which is flowing through the tunnels 9, 9 with the result that air is pulled through the openings i9 and in passing downwardly through the openings I8 in the bottom of the boat, serves to relieve the bottom of the boat to a considerable extent of the effects of suction resistance, with the result that thestern portion of the-boat will ride higher and in oflering less resistance will tend to promote increased speed without the expenditure ofmore power.

Air continuing through the tunnels 9 is expelled through the stern opening I3 with the result that the opportunity for vacuum to occur at this point is practically diminished.

Thus it can be seen that by having the bow open to capture air, bow resistance is cut considerably, and that incident to this, the air that is captured is utilized for dissipating suction under the hull, as well as stern vacuum.

As a boat improved in the manner above explained slows down, the water begins to rise in the water trap with the result that a ballasting efiect takes place automatically.

The bow of the boat is so shaped and formed with respect to the opening I I that at high speed the mouth or opening I l is taking in a maximum of air and the other resistance relieving factors above explained are functioning at a corresponding ratio of efficiency.

As is apparent in Fig. 4, the bow of the boat is of inverted U shape and as this form approaches the stern, it gradually transforms into a modified U-shape, the upwardly converging side portions of which are slightly convex as. at 2! for a substantial distance aftward. Gradually the side portions 2| merge into plane surfaces and the bottom assumes a flattened. but inverted V-shape as depicted in Figure 7. From the openings I8 in the boat bottom, the inverted V-shape gradually flattens out to a transverse plane or substantially flat bottom, at the stern, as shown in Fig. 9.

The rearwardly diminishing flat portion 12 and the bulged portions 2| have a certain coefiiciency toward fanning out the air under the craft to reduce water resistance.

As the flat area [2 narrows out toward amidship, the slightly bulged portions 2! substantially flatten out, and at about the bottom openings l8 join the general; concave contour of the boats bottom. The depth of this aft bottom concavity decreases to an almost flat stern bottom.

The intake of air at the bottom of the boat is dependent upon the speed of water passing across the opening, the vacuum increasing in accordance with the increase in speed.

The intake of air is automatic and the percentage thereof will vary in accordance with the speed, hence the amount of air taken in is automatically controlled and is governed by the proper size of the port for the maximum intake of air at any speed above approximately twenty miles per hour.

Having described the claimed as new is:

1. In a, boat, an inverted U shaped bottom extending from the bow aftward, said bottom gradually transforming to an inverted modified U formation with the converging side portions thereof being convex in shape, said convex side portions gradually transforming to converging plane surfaces toward amidship, said bottom gradually fading to a flattened out inverted V- shape amidship and from there gradually fiattening out to a transverse plane at the stem.

2. In a boat having a hull, a forward compartment in the hull, a passenger compartment, and an engine compartment to therear of the pasinvention, what is senger compartment, the hull having an inverted U-shaped bottom under the forward compartment, said bottom, gradually transforming to an inverted modified U formation under the forward compartment with the converging side portions thereof. being convex in shape, said convex side portions gradually transforming to con.- verging plane surfaces under the passenger cornpartment, said bottom gradually fading to a flattened out inverted V-shape under the passenger compartment and from there gradually flattening out to a transverse planeat the stern.

3. In a boat having a hull, an inverted U shaped bottom extending from the bow aftward, said bottom gradually transforming to an in verted modified U.-shaped formation with the converging side portions thereof being convex in shape, said convex side portionsgradually trans.- forming to converging plane surfaces amidship, said bottom gradually fading tov a flattened out inverted V-shape amidship, a water trapformed in the hull amidship thereof, an opening in the bottom under the water trap in said flattened out section, said bottom gradually flattening out to a transverse plane from amidship towards the stem.

4. In. a boat having a hull, an airinlet in the forward portion of the hull comprising a grillwork on either side of the hull, an inverted; U- shaped bottom havinga lip extending forwardly to the grillwork, said bottom gradually transforming to an inverted modified U-shaped formation with the converging side portions thereof being convex in shape, said convex side portions gradually transforming to converging plane surfaces toward amidship, said bottom gradually fading to a flattened out inverted V- shape amidship and from there gradually fiattened out to a transverse plane at the stern.

HARRY H. GARMONT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 961,750 Branth June 21, 1910 Number 15 Number 

